Devices for processing an initial liquid medium comprising cells in an initial concentration to obtain a product liquid medium comprising cells in a product concentration and corresponding methods are known. The devices typically comprise a separator adapted to separate the initial liquid medium into various constituents, a first supply system for supplying the initial liquid medium to the separator, a first outlet system for extracting the product liquid medium from the separator, a sensor adapted to measure a physical parameter related to the concentration of the cells in the initial or product liquid medium, and a control unit coupled to the sensor and adapted to control at least one process parameter of the device as a function of the physical parameter measured by the sensor.
Such devices are typically used for separating blood into various constituents, in particular for extracting red blood cells (erythrocytes) as described for example in EP 0 528 238 B1. The known device for the separation of blood into various constituents is adapted for in-vivo-processing, in particular for intraoperative blood processing and comprises a separator which has one intake line with a pump and a discharge line for the erythrocyte fraction. To control the pump of the intake line, a sensor for a continuous measurement of the hematocrit value is provided in the intake line. The measured hematocrit value serves as an input for regulating means. The output of that regulating means is used to adjust the blood flow through the pump depending on the measured hematocrit signal.
It is an object of the present invention to improve such device such that it can be used for in vivo and in vitro processing of an initial liquid medium comprising cells in an initial concentration to obtain a product liquid medium comprising cells in a product concentration.